Apparatus for cooking pulp-making fibers



Aug. 5 1924.

T. B. MUNROE.

APPARATUS FOR COOKTNG PULP MAKING FIBERS Original Filed Dec. 5 49?": 7 Sheets-Sheet 1 T. B. MUNROE APPARATUS FOR COOKING PULP MAKING FIBERS Original Filfld 8 5. 1921 7 Sheets-Sheet 2 Aug. 5 R924, 1,503,549

T. BLMUNROE -APPARATUS FOR COOKING PULP MAKING FIBERS Original iled ec- 3. 1921 7 Sheets-Sheet 5 I mmpr miil-l I ll T. B. MUNROE APPARATUS FOR COOKING Pup? MAKI NG FIBERS Original Filed Dec. 5. 1921. 'T'-Sheets-$heet 4 Aug. 5, 192 4. 1,503,549

T. B. MUNRQE APPARATUS FOR COOKING PULP MAKING FIBERS Original Filed Dec. 5. 1921 7 Sheets-Sheet 5 Aug 5 1924. 1,503,549

'r. a. MUNRQE .APPARATUS FOR COOKING PULP MAKING FIBERS Origihal Fil ed mic/s. 19 1 7 Sheets-$heet 6 T. B. MUNROE APPARATUS FOR COOKING PULP MAKING FIBERS Original ile d Dec. 5. 1921 7 Sheets-Sheet '7 aw/IIIA'IIIIIIIIIIIIIIIIfl/II Patented Aug. 5, 1924.

UNITED STATES PATENT OFFICE,

TREADWAY B. M'UNBOE, OI

APPARATUS FOR COOKING PULP-MAKING- FIBERS.

Application filed December 3 1921, Serial No. 518,747. Renewed June 20, 1924.

To all whom it may concern:

Be it known that I, TREADWAY B. MUNBOE, a citizen of the United States, residing at Forest Glen, in the county of Montgomery l and State of Maryland, have invented certain new and useful Improvements in Apparatus for Cooking Pulp-Making Fibers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to apparatus for cooking pulp making fibers and has for its object toprovide an apparatus of this character which will be simple in construction, comparatively inexpensive to manufacture and more eflicient in use than those which have been heretofore proposed.

With these and other objects in view the invention consists in the novel details of constructiori and combinations of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification, in-which like numerals designate like parts in all the views a Figure 1 is a diagrammatic plan view of an apparatus made in accordance with the present invention;

Figure 2 is a side elevational view of th pai'Pts shown in Figure 1;

1 8 view, on an enlarged scale, through the caustic tank and intake end of the first cook ing drum, taken on the line 3-3 of Figure 1, and looking in the direction of the arrows;

Figure 4 is a view similar to Figure 3 of the outlet end of the first cooking drum, and of the connection between-the first and second cooking drums, taken on the line 4-4 of Figure 1;

Figure 5 is a transverse sectional. view through the caustic tank taken on the line 55 of Figure 3; a

Figure 6 is a view. similarto' Figure 5 through the connection between the caustic tank and the first cooking drum, taken onthe line 6-6 of Figure 3;

Figure 7 is a transverse sectional view through the end connection between the first and second cooking drums, taken on the line 77 of Figure 4;

gure 3 is a central vertical sectional Figure 8 is a detail side elevational view of one of the paddles or agitating members employed in the caustic tank, cooking drums and wash tank;

Figure 9 is a top plan view of the parts shown in Figure 8' Figure 10 is a side elevational view, partly 1n section, of'the drum or roll employed to transfer the fibers from the caustic tank to the first cooking drum;

Figure 11 is a transverse sectional elevational view of the parts shown in Figure 10, taken on the line 11-11 of said Figure;

Figure 12 is a central vertical sectional view, partly broken away, of the wash tank, and its associated parts, shown in Figures 1 and'2;

Figure 13 is a transverse sectional view through the intake end of the wash tank' and outlet endof the second cooking drum, taken approximately on the line 13-13 of Figure 12;

Figure 14 is a fragmentary detail sectional view of a portion of the caustic tank and drum illustrated in Figures 1, 2, 3, 5 10,

and 11, showing the seals employed to pre vent the escape of fiber past said drum;

Figure 15 is a detail side elevational view 0f one of the conveyors employed in the wash tank; 7 35 Figure 16 is a transverse vertical sectional view of the parts shown in Figure 15, taken on the line 16-16 of said Figure 15; Figure 17 is a fragmentary plan view of the arts shown in Figure 15; and

F1gure'18 is a transverse vertical sectional view taken on the line 1818 of Figure 15, looking in the direction of the arrows.

In the production of pulpfor various purposes from bagasse and other analogous fibers, it has been recently proposed to cook the fibers with a comparatively weak solutionof caustic soda at atmospheric pressures for relatively short periods of time, instead of following the former methods of cooking with from 20% to 50% solutions of caustic at pressures considerably above the normal. atmospheric pressure, to the end that the cost of production is appreciably reduced while at the same time the strength and efliciency of the'fibers for the particular pur-v poses in hand is materially increased. Thepresent apparatus is particularly adapted for carrying out such a process, and furthermore, is so constructed as to provide for the conservation of the cooking liquor in so far' as it is possible, as well as to permit of the process being carried on continuously 1nstead of intermittently as was the case with the older pressure processes.

Referring more particularly to Figures 1, 2, 3 and 4 of the drawings, 1 indicates a re ceptacle or tank adapted to receive and hold a caustic solution, which in the new process above mentioned may range from say 2% to 10%. The said tank 1 may be provided with the side walls 2 and 3', and with the end walls 4 and 5, the latter of which preferably does not extend the full height of' the tank, as will be clear from 'Figure 3. Journalled in the sides 2 and 3 in close proximity to the end wall 5 is a drum or roller 6, comprising the spiders 7, rigidly mounted on the shaft 8, adapted to be driven from a power shaft 9 as by the bevel gears 10 and 11, see Figure 1. The said spiders 7 are suitably joined together by the slats or strips 12 which form supports for the Wire cloth or other foraminous covering 13, all as will be clear from Figures 10 and11.

Suitable seals are provided to prevent the escape of the fibers past the ends of the drum 6, adjacent the walls 2 and 3, of the tank 1. These seals, as is best shown in Figure 14, comprise angle bars 140, curved to the same radius as the drum 6, and secured to the said walls of the tank 1. A strip of felt, leather, or other yielding material 141, baeked by a metallic strip 142 is clamped or secured to the said angle members 140 by the clamping strip 143, and overlaps the edges of the end spider members 7, thereby providing a sliding joint which effectively prevents the escape of fibers between the walls 2 and3, and the ends of the drum 6.

The caustic tank 1 is rigidly secured to one end of the first cooking drum 15, as is best shown in Figures 1, 2 and 3,-which drum preferably takes the form of apair of horizontally disposed spaced cylinders 16 and 17 providing an annular space 18 for the circulation of a heating fluid. The said drum is provided at its other end with an open tank or connection 19, leading to one end of the second cooking drum 20, see Figure 1, which drum 20 may be of a construction similar. to the drum 15. The other end of the said second drum 20 is provided with an open connection 21 leading to the wash tank 22, which tank may be of a construction similar to the caustic tank 1, having the side walls 23 and 24, and the end walls 25 and 26, as best seen in Figures 1, 2 and 12. The said wash tank 22 is preferably inclined somewhat from left to right, as will be clear from the said Figures 2 and 12, and is provided with a plurality of transverse partitions or walls 27, 28, 29 and 30, providing therein the chambers 31, 32, 33, 34

and 35. The chambers 31, 33 and 35 constitute drainin compartments, while the chambers 32 an 34 constitute the wash tanks proper, all as will appear more fully below.

he partitions or walls 25, 26, 27, 28, 29 and 30 are all of substantially the same height but owing to the inclination of the tank 22, different liquid levels are maintained in the various chambers or compartments, as will likewise presently appear.

Mounted between the Walls 23, and 24 of the wash tank 22 and above the chamber 31, is an inclined slatted conveyor which is adapted to receive the mixture of fibers and cooking liquor as it flows from the connection 21 over the end wall 25, to separate the fibers from the liquor, which is returned to the cooking drums, and to transfer the said fibers to the fresh water chamber 32 for washing. The fibers which are suspended in the liquid are caught and deposited upon the slats 41 of the said conveyor, which slats are carried b a pair of endless chains 42 and 43, see F igures 15 to 18, passing between a pair of pressure rolls 44 and 45 suitably journalled in a frame 46 secured to the walls 23 and 24 of the tank 22. The said chains 42 and 43 and the slats 41 pass around the driving sprockets 47 and 48 mounted upon a shaft 49, and around the idle sprockets 50 and 51 mounted upon a shaft 52, the shafts 49 and 52 beingjournalled in the frame 46 in any suitable manner. The shaft 49 may be driven in any desired manner, as by the bevel gears 53 and 54 and power shaft 55.

The ends of the slats 41 project beyond the chains 42 and 43 and may slide along and be supported by the angle iron side members56 and 57, see Figures 12, 15, 16, 17 and 18. The lower press roll 45 preferably takes the form of a plurality of spaced pulleys rigidly mounted upon the shaft 60 be tween the chains 42 and 43, and forming a support for the middle portions of the slats 41, while at the same time permitting of the free escape of water between the said slats,

as will appear more fully below. The said lower roll 45 may however, if desired, be madesolid, similar to the top roll 44, which preferably is in the form of a single cast iron cylinder of a length substantially equal to the length of the slats 41, as will be clear from Figure 16.

The said top roll 44 is mounted directly above the lower roll 45 on the shaft 61, journalled in the bearing members 62 which are pivoted to the uprights 63 rigid with the frame 46, see Figure 15. The pressure exerted by the roll 44 upon the fibers carried by the slats 41, other than that due to its own weight, is readily controlled by the compression springs 64 surrounding the pivoted rods 65, between the ends 66 of the bearing members 62 and the hand wheels 67 threaded on the said rods 65, as will be readily apparent. 68 designates a plurality of idler rolls mounted on the shaft 69 j'ournalled on the frame 46 which rolls are adapted to support the, slats 41 and chains 42 and 43, on their return flight, see Figures and 17. a

Conveyors 70 and 71, similarin every respect to the conveyor 40 are mounted respectively in the chambers 33 and 35, the con- 'vey'or 70 draining the fibers after they have been subjected to .thewashing action'of'thewater in the chamber 32 and transferring them to the washing chamber'34' where they are a ain washed, after which they flow over t e partition 30 onto the conveyor 71 a I which again drains them, and discharges ency of the fibers to settle to the bottom; g of the, cooking liquor, and in order to prethem into any suitable receptacle, not shown, ready for the next step in the, particular process being followed.

0 conveyors and 71 are provided with the driving shafts 72 and 7;; respectively which may be driven by the pairs of bevel gears '74 and 75, and 76 and 77,

from the power shaft 55,.as will hc clear from Figures 1 and 2.

The cooking of the fibers when following out the new process above mentioned is reiativcly rapid-as compared to certain of the.

older methods, being com'pletedin from say 1 to 3 hours. However, even in this relatively short time, there -is amarked'tend vent such settling, suitable agitators are provided within the caustic tank, the cooking drums and the wash tanks.

These said agitators mayebe of any desired form, but, are here shown as comprisingthe longitudinally extending shafts 80 within the caustic tank 1 and first'cooking' ing drum 20 and is provided with the arms a or paddles 186, and" the shaft 82 is mounted on the axis of the-wash tank 22 and pro vided with the arms or paddles87. The shafts 80 and 81 are-"driven from the power shaft 88 by means of the pairs of bevel gears 89 and 90, and 91 and 92 respectively :and the shaft '82 is driven from apower shaft 93 by means of'the bevel gears 94 and 95, as

will be clear. from Figures 1 and 2. k

The conservation of the caustic is an important feature of this invention, and to this end a system of piping is provided connecting the various chambers of the wash tank 22 and the cooking drum 15, whereby any surplus caustic material which may be carried from the cooking drums to the wash tank is returned to the said drums,

as will now be disclosed.

Leading from the compartment 35 of the wash tank 22 is a discharge pipe 100 provided with a valve 101, adapted to control the flow of liquid therefrom. The said pipe 100 is also provided with a T connection 102 from w ich leads a pipe 103 running parallel-ate the axis of the wash tank 22. y

The pipe 103 is provided with a branch 104 extending upwardly andover the side of the wash tank-22 and discharging into the compartment 34, see Figures 1 and 2. The said pipe 103 is also provided with an exten-- sion vv105 leading up over the side of the wash tank and discharging into the compartment 32. ,5.

I In like manner, a pipe 106 leads from the compartment 33 and is provided with a control, valve .107 and a T connection 108 from which leads a pipe 109 provided with an upward .extension, 110, also discharging into the compartment 32. A pipe 111 leads from the compartment 31' and is provided with a discharge controllingvalve 112 and with a connection 113, from which vleads a pipe 114, discharging into the open connection 115 between the caustic tank 1' and the cooking-drum 15." A compressed .air. pipe 116 is provided with branches" "117, 118, 119 and 120' leading re spectively into the upwardly extending pipes 104, 105,110, and114, whereby the liquid within said last mentioned pipes ,may be elevated over the side of the wash tank as will, presently appear. v 1

the meshes of the foraminous cloth 13 on the feeding drum 6 to the'interior ofthe said drum, is returned to the opposite end of the tank lbymeansof the pipes 125 and 126 leading from the side of the tank 1 adjacent the drum 6. The said pipe .125

.Thev caustic liquorwhich passes through is provided with the upwardextension 127 1 discharging over the side 3 of thc'said tank intothe interior thereof, and a branch 121 I of therair pipe 116 enters the said pipe 127 forwthe purpose of elevating the liquid there- 1n. i

Steam' or other heating v fluid may be introduced into the annular space 18 of the 0 cooking drum 15 and into'the similar space, not'shown, of-the drum 20 through the connections 130 and 131 respectively, see Figure 1, and-may escape therefrom through ,the connections 132 and 133' respectively,

see' Figure 7. Suitable outlets, such as 135,

136, 137, 138,-and' 139controlled by valves not shown are provided topermit of the various tanks andv compartments being drained for "cleaning "and repair purposes.

The operation of the present invention will be clear from the foregoing but may be briefly summarized as follows Referring more especially to Figures 1, 2, 3, 4 and 12, the tank 1 is filled with a caustic solution of suitable strength, say from 2% to 10% until the roll 6 is approximately one third submerged. Fresh water is introduced into the cooking drums 15 and 20, the connecting tanks 19 and 21, and the chambers 32 and 34 of the wash tank 22. Bagasse or other fibers are introduced by any suitable means into the caustic liquor within the tank 1 and the agitators 85 as well-as the feeding drum 6 are set in motion. The fibers will be thoroughly mixed with the said caustic liquor and will travel from left to right as seen in Figure 1, until they reach the said drum 6. Here the liquor will pass through the openings in the toraminous surface 13 While the fibers will be deposited thereon and will be carried upwardly and to the right as seen in Figures 2 and 3. They will next be thrown from the drum 6 over the partition 5 into the tank 115 between the caustic tank 1 and the first cooking drum 15 and will pass into the interior of the said drum. Steam being admitted through the connections 130 and 131 into the annular spaces 18 of the said drums the temperature of the liquid and fibers therein is raised to say from 150 to 212 F., or higher. The mixture now passes through the first drum 15 from left to right as seen in Figure 1, into the connection 19 and from there it enters the second drum 20 through which it passes from right to left, finally reaching the open connecting tank 21 leading to the wash tank 22. From the tank 21 the mixture flows over the partition 25 onto the overlapping horizontally disposed apron 200, see Figure 12, onto the slats '41 of the conveyor 40 upon which the fibers are deposited, the liquid draining through the spaces between the said slats and being retained within the compartment 31'. The said conveyor 40 moves the fibers from left toright as seen in Figures 2, 12 and 15, and at the same time elevates them above the liquid level in said tank 31, carrying them over the partition 27 and depositing them into the wash water within the compartment 32. After being subjected to the action of the wash water within this last mentioned compartment for a suitable length of time, they pass over the partition 28 onto the conveyor 70 where they are again drained or separated from their liquid which is caught in the compartment 33, and the said fibers are then deposited over the partition 29 into the compartment 34. This said compartment likewise contains wash water which again washes the fibers, removing therefrom the remaining caustic cooking liquor after which they flow over the partition 30 on to the slats of the conveyor 71 which separates the wash water from the fibers, the water bein retained in the compartment 35 and the bers being de osited from the conveyor 71 into any suita le receptacle not shown for further treatment.

The agitators 85, 186 and 87 within the various tanks and drums are continuously rotated during the process just described and serve to keep the fibers intimately mixed with the liquid and to prevent their settling to the bottom. As above stated, the conservation of the caustic cooking liquor is an important feature of this invention and it is accomplished as follows: The fibers are first drained and separated from a portion of the liquor in the tank 1 by means of the forammous roll 6 and they intentionally carry another portion of the said caustic liquor over the partition 5 into the cooking drums. This is necessary inasmuch as the cooking is carried on in the presence of a small percentage of caustic in order to soften the fibers without disintegrating them. After the cooking step 1s completed, however, it is desirable to save as much of the caustic liquor as is possible and to this end it is returned to the tank 115 from the chamber 31 of the wash tank 22 after being drained from the fibers by the conveyor 40.

It is also necessary that the fibers be then washed to prevent further action of the caustic upon them in order to preserve their strength and the Water Which'is used to wash the fibers may be returned into the cooking drums as soon as it reaches the desired concentration.

That is to say, when the fibers are sepa-- rated from the cooking liquor after leaving the cooking drum 20, by the conveyor 40, the said liquor is collected in the compartment 31 of the wash tank 22, and may be of a strength only slightly less than that in the tank or connection 115. In order to return this said liquor to the tank 115, as above mentioned, the liquor in the compartment 31 enters the pipe 111, the connection 113 and pipe 114, the valve 112 being closed, and as the liquid level within the compartment 31 rises it likewise rises in the vertical portion of the pipe 114.

When the liquid level approaches the top of the partition 27 within the wash tank 22, the valve controlling the branch 120 of the air supply pipe 116 is opened, whereby compressed air is admitted into the pipe 114 forcin the liquid upthrough the said pipe from t 1e compartment 31 into the tank 115 in the well known manner. This operation may be either intermittent or continuous, depending upon the rate at which the liquid is collected in the chamber 31, and upon the amount of air admitted to the pipe 114.

The fibers after having been drained and pressed by the conveyor 40 and its pressure roll 44 have lost a large portion oftheir free'caustic and are deposited into the wash water in the compartment 32 which of course removes an additional quantity of caustic. As they leave this compartment they are again drained and pressed by the conveyor 70 and its associated pressure rolls, the liquid being collected in the compartment 33 asabove stated. The said liquid now enters the pipe 106, conne:tion 108 and pipes 109 and 110, the level within the said pipe 110 of course being the same as 1n the compartment 33 when the valve 107 1s closed. The liquid may be forced from the said pipes by air pressure admitted to the pipe, 110 from the branch 119 of the alr pipe 116,

being returned to the compartment 32 where it is used over again.

in the compartments 32 and 33 approaches a concentration which warrants the recovery of its caustic whereupon it may be withdrawn from the wash tank 22 by opening the valve 107, and either stored in a suitable receptacle for future use or concentrated for reuse in tank 1.

like manner, the wash water in the compartment 34 is drained and pressed from the fibers by the conveyor 71 and its press rolls, and collected in the compartment 35 from which it may be returned either to the said compartment 34 by means of the pipes 100 103 and 104 and air pipe 117, or when desired to the compartment 32 by means of pipe 105 and air pipe 118.

The said water in the compartment 34 of course will not receive as much caustic from the fibers-as does that in compartment 32 and it will therefore be longer in approaching the above mentioned concentratlon. It

the tank 1 which passes through the foraminous surface of the drum 6 to the interior ma escape therefrom through the pipes 125 an 126 and be returned b way of the pipe 127 to the left hand end 0 the said tank, as

above disclosed.

7 It will thus be seen that there is provided an aparatus suitable for carrying out the above mentioned process continuously and relatively rapidly; that the entire apparatus is open to the atmosphere and adapted to be operated at atmos heric pressures, which is highly desirable or continuous and efiicient operation; and that the total efliciency is furt or increased by the provision of means for the conservation of the caustic cooking liquor.

It isobvious that those skilled in the art may vary the details of construction as well as the arrangement of parts without departabove disclosure except as may be requiredby the claims.

What I claim is 2- 1. In an apparatus for continuously preparing vegetable fibers the combination of a tank open to the atmosphere adapted to receive and hold said fibers and a solution capable of reacting thereon; a second tank comprising an open ended drum, adapted to' receivesaid solution and fibers from said first tank; means comprising a travelling foraminous surface adapted to transfer said fibers from saidfirst to said second tanks;

. means for heating said second tank; means After repeated use, the wash water withfor separatin said fibers from said solution; means or returning said solution to said second tank; and means also open to the atmosphere associated with said tanks adapted to wash any surplus solution from said fibers, substantially as described.

2. In an apparatus for continuousl preparing vegetable fibers the combination of a tank open to the atmosphere adapted to receive and hold said fibers and a solution capable of reacting thereon; a second tank comprising an open ended drum, adapted to receive sald solution and fibers from said first tank; means comprising a travellin foraminous surface adapted to transfer sai fibers from said first to said second tanks; means for heating said second tank; means for separati said fibers from said solution; means or returnin said solution to said second tank; means a so open to the atmosphere associated with said tanks ada ted to wash any surplus solution from sai fibers; and rotatable agitating means within said tanks and washing means, substantially as described.

3. In an apparatus for continuously preparing vegetable fibers the combination of an open tank adapted to receive a mixture of said fibers and a solution capable of reacting thereon; a heating drum comprising a pair of open ended s aced cylinders a apted to hold a cooking liquor and to receive said fibers from said tank; means comprising a rotatable foraminous surface, adapted to remove said fibers from said solution and to transfer them to said drum; means for supplying a heating fluid to the space between said cylinders; and means comprising open wash tanks adapted to remove any surplus liquor from said fibers, after they have been heated, substantially as described. 4. In an apparatus for continuously preparing vegetable fibers the combination of an open tank adapted to receive a mixture of said fibers and a solution capable of reacting thereon; a heating drum comprising a pair of en ended s aced cylinders,

adapted to ho d a cookin i uor and to receive said fibers from sai tan means comprising a rotatable foraminous surface adapted to remove said fibers from said solution, and to transfer them to said drum; means for supplying a heating fluid to the space between said cylinders; means for separating said fibers from said liquid after they have been heated; means for returning the separated liquor to the heating drum; and means comprising open was tanks adapted to remove any surplus liquor from said fibers, substantiall as described.

5. In an apparatus or continuousl preparing vegetable fibers the combinatlon of an open tank adapted to receive a mixture of said fibers and a solution'capable of reacting thereon; a heating drum' comprising a pair of open ended spaced cylinders, adapted to hold a cooking liquor. and'to receive tank; means comprissaid fibers from sai ing a rotatable foraminous surface adapted to remove said fibers from said solution and,

anda caustic solution; a heating drum com-- prising a pair of open ended spaced cylinders adapted to hold a caustic cooking liquor; means comprising a hollow roll havin a foraminous surface adapted to remove said fibers from said caustic solution in tank and to transfer them to said drum; means for supplying steam to the space between said drum cylinders; means com rising a travelling slatted conveyor adapte to drain said liquor from said fibers after they have been cooked; means for returning said drained liquor to said drum; and means comprising a plurality of wash tanks and travelling slatted conveyors for removing any surplus liquor from said fibers, substantially as described.

7. In an apparatus for continuously preparing vegeta 1e fibers the combination of an open tank adapted to receive said fibers and a caustic solution; a heating drum comprising a pair of open ended spaced cylinders adapted to hold a caustic cooking liquor; means comprising a. hollow roll having a foraminous surface adapted to remove said fibers from said caustic solution in tank and to transfer them to said drum; means for supplyin steam to the space between said drum cy inders; means comprising a travelling slatted conveyor adapted to drain said liquor from said fibers after they have been cooked; means for returning said drained liquor to said drum; means com prising a lurality of wash tanks and travellin s atted conveyors for removing any surp us liquor from said fibers; and rotatable agitating means within said tanks and drum, substanially as described.

In testimony whereof I aflix my signature,

TREADWAY B. MUNROE. 

